Anthuriums are the centrepiece of attraction in many indoor gardens.
But sometimes, the exotic beauty of this plant is tarnished by the yellow and brown shades or spots that occur on some of the leaves.
The first instinct is to cut those leaves. But, what if some other leaves start to turn yellow and brown in the next few weeks?
Instead of hiding the problem, you should try to address the root cause of the yellowing so that your plant will stay healthy for a long time.
And, in this article, I’m going to share with you the 9 scientifically proven causes of anthurium yellow leaves.
Reasons For Anthuiurm Yellow Leaves
The yellowing of anthurium leaves is a sign of many plant problems. The most common reasons include overwatering, too much sunlight, overfeeding, dry air, temperature shock and poor soil mixture. Just by analyzing the conditions, you can identify the problem. Most of the time, making small adjustments in the care routine will fix the issue as well.
Let me explain briefly about each of the reasons so that you can understand which one is causing your anthurium leaves to turn yellow and brown.
Additionally, I will also mention the scientifically recommended solution to fix the root causes of all the reasons.
1. Watering Issues
Watering issues are by far the most commonly seen reason for anthurium leaves turning yellow in the western world.
These include both overwatering and underwatering. Even though they both can make discoloration in anthurium leaves, overwatering is considered to be more evil of the two.
According to one research published in the Clemson Cooperative Extension, overwatering your anthurium plants will replace the air in the soil pockets with water. As a result of this, the root of your anthurium plant is deprived of oxygen.
In the Ask a Biologist column of Arizona University, it is mentioned that when the roots of your anthurium plants are standing in the water without access to oxygen, the chlorophyll in the leaves starts to break down. As a result, the leaves turn yellow, brown or dark red in some cases.
Overwatering is a very serious issue, because it may trigger root rot in anthurium which may kill the plant if untreated.
Now coming to underwatering, even though it is not as common as overwatering, still it can cause the leaves of anthurium plants to turn yellow and brown.
When you underwater your anthurium plant, the plant is not getting enough energy to produce and maintain the chlorophyll pigment. As a result, discoloration happens.
How to fix watering issues?
The only possible solution to fixing the watering issue is to set up a watering schedule for your anthurium based on the plant’s requirements.
Do not follow any strict rules found on the internet. Instead, listen to your plant.
Being tropical plants, anthurium thrives when the soil is dry to slightly moist. So whenever the top one to two inches of the soil mixture is dry, water your plant. Depending on your local climate and seasonal changes, it may vary from weekly once to maybe every other day.
Apart from setting up a proper watering schedule, you also need to make sure that your potting soil has good aeration and drainage capability. Also, pots must have drainage holes to flush out excess water.
2. Too Much Light
If you’re pretty confident about your watering schedule, then the next common culprit of anthurium leaves turning yellow is light and temperature issues.
Too much light or too little light can cause yellow leaves in your anthurium plant. But most of the time, too much light is the culprit.
When your plant receives too much direct sunlight, the UV light will make the leaves dehydrated and the colors start to fade. According to TNAU Horticultural Portal, even 3 to 4 hours of direct sunlight for a week can develop discolouration in the anthurium leaves.
In the beginning, the dark green color turns to pale green, then pale yellow and prolonged sun exposure will make them dark brown. At some point, the leaves will completely dry and wilt.
One good thing about sunburn is that it will affect only the spot where the harsh sunlight falls. For example, if only one side of your anthurium is exposed to direct sunlight, then only leaves in that region will have yellow and brown leaves.
This makes it pretty easy to find whether the problem of anthurium yellow leaves is due to sunburn or any other reason that we discuss in this article.
How to fix lighting issues?
Fixing the problem of too much sun is pretty easy.
If you found out that your anthurium is getting too much sunlight, then simply move the plant to a spot where it gets less intensive light. If you have east-facing windows in your room, then that is a perfect spot.
Alternatively, you can use a curtain or synthetic light shield to reduce the intensity.
If you do not find a way to reduce the intensity of natural light, then move your plant somewhere interior and provide LED grow light. It is recommended to provide 10 to 12 hours of 1500 to 2000 fc of artificial light for anthuriums to thrive (3).
Check out our dedicated article on anthurium light requirements to provide the best light for your plant to thrive.
3. Improper Humidity Levels
If you check any thread or forums about houseplants, one of the common complaints that many people from colder regions is that their anthurium leaves are turning yellow during the winter months.
And, the reason is low humidity or in other words dry air.
Let’s face the truth. Dry air is not ideal for your anthurium plant.
Anthurium plants come from tropical forests where the humidity is above 70 throughout the year. In fact, in some forests of Peru, during summers the average humidity is recorded to be in the range of 95%.
You don’t want to have 95% humidity inside your home, but according to studies, the anthurium plant needs at least 50% humidity to live healthily. If you want them to thrive, then you should aim to provide a minimum of 60% humidity (3).
During the winter season, all the heating appliances that your use in your home push out dry air all the time which makes the overall humidity inside your home very low. And, this is why your anthurium leaves turn yellow during the winter season.
How to fix low humidity issues?
Fixing low humidity is very straightforward. If you have the budget, you can install a humidifier in the room where you have your anthurium plant.
If you want some cheaper options, then you can try out frequent misting, pebble tray arrangement, or moving your humidity loving plants close to each other.
4. Lack of Fertilizer
Lack of enough nutrition can mess up the health of anthurium leaves in a big way.
In the tropical forests, anthurium plants grow above layers of leaf mould and animal matter which gives them continuous access to nutrients (1). But when you grow them indoors, all they get is what you give.
A lot of people refrain from chemical fertilizers thinking that they are bad for plant health. Even though many studies have debunked this myth stating diluted water-soluble fertilizers are necessary for plant health.
The most important nutrients needed for plant growth are Nitrogen, Phosphorous and Potassium. The commercially available fertilizers are a combination of these chemicals.
Based on a study published in Whatcom County Extension of Washington State University, the yellowing of anthurium leaves is due to a deficiency in nitrogen.
Nitrogen is one of the key elements needed for plants to generate chlorophyll, the pigment behind the green color of leaves. So, a deficiency in nitrogen causes the formation of chlorophyll to slow down and as a result, discoloration happens.
How to fix a lack of nutrition?
The best way to fix the lack of nutrition for your anthurium plants is to provide nutrient-rich soil in the beginning.
But the nutrients in the soil will deplete over time. So, in order to give your plant a continuous supply of nutrition, frequent fertilization is very important.
A well diluted NPK fertilizer (30:10:10) is recommended once a month during the growing season. For every part of fertilizer, three or four parts of water should be added.
5. Bad Soil Mixture
If you have a bad soil mixture, you cannot expect your anthurium to grow fine.
A bad soil mixture for your anthurium can be a poorly mixed soil or a properly mixed-aged soil mixture.
When you have a soil mixture with a lack of aeration, the roots of your anthurium do not get enough oxygen to carry out the normal plant functions. As a result, anthurium leaves turn yellow and brown.
If the soil lacks water retention capability, the water will drain out very quickly even if you overwater. This makes the situation similar to underwatering and causes discoloration in anthurium leaves.
Similarly, if the soil is very damp and lacks proper drainage capabilities, it will create a situation similar to overwatering. The roots will be sitting in the damp waterlogged soil and will not be able to suck enough nutrients and oxygen leading to anthurium yellow leaves.
How to fix the bad soil mixture problem?
The only recommended way to fix bad soil problems is to repot your anthurium in a new pot and fresh soil. If old nutrient-depleted soil is the problem, then adding fertilizer may solve the issue temporarily. But still, repotting in fresh soil is a better solution.
You must try to provide a proper soil mixture tailor-made for anthurium plants.
If you don’t have time for creating your own soil mixture, then consider purchasing a pre-made anthurium soil mixture from your local nursery or online stores.
On the other hand, if you prefer to have full control over your plant, then mix a soil mixture that has proper aeration, drainage capability and enough water retention capacity.
A soil-less mixture with equal parts of peat moss/coconut husk, perlite, pine bark and leaf mols will be sufficient enough. But, make sure that you are fertilizing the plant frequently and change the mixture once every two years.
6. Temperature Shock
When your anthurium is subjected to extreme hot or cold conditions, it will have a toll on the health of the plant.
As I mentioned multiple times, anthuriums are native to tropical conditions where they are exposed to warmer temperatures throughout the year. For the anthurium to thrive, 77 oF to 86 oF (25 oC to 30 oC) is recommended.
Even though anthuriums can tolerate lower temperatures, they won’t grow well. Once the temperature goes below 50 oF (10oC), anthurium leaves start to turn yellow and brown. And, prolonged exposure to chilled air will make the leaves curly, wilt and dry.
How to fix temperature shock?
If you live in a completely colder region, then it’s advised to keep your plant in a room where you have access to room heaters 100% of the time.
On the other hand, if you experience cold waves for only a couple of weeks or months during winters, then move the plant to a warmer region during cold waves.
It may seem like temperature stress may not be a reason for anthurium leaves turning yellow in warmer regions. But when your anthurium is in a spot where it’s in contact with cold air from air conditioners or coolers all the time, it may trigger discolortion in leaves.
7. Excessive Salt Buildup
Adding a well-balanced fertilizer to your anthurium is very good for accelerating plant growth.
But, many times beginner plant parents tend to overfeed their anthurium thinking that it will increase the growth rate. When you overfeed your anthurium plant with too many fertilizers, these chemicals form a white crust and block the aeration of roots which will prevent roots from sucking necessary nutrients.
Not just over-fertilization, watering your plants with mineral treated water can also cause brown and yellow leaves in anthurium due to salt buildup. If you are using tap water for your anthurium, then it may cause this issue since most states treat the water before distributing it.
How to fix salt buildup issues?
First thing is to add fertilizer only when your plant needs it. If you have a good potting mix with peat moss or coconut husk, then fertilizing monthly once is more than enough.
Also, have a look at the concentration of the nutrients in your fertilizer. For anthuriums, an NPK (30:10:10) fertilizer is the recommended option. Also, always dilute it with water before applying.
On the other hand, if the salt buildup is due to using municipal tap water, then it’s really hard to fix. If you have access to underground water, that would be great for your plants. Or you can store rainwater and use it.
If you do not have any choice apart from tap water, then one day before watering fill a container with water and keep it somewhere undisturbed. Over time, some salts will settle down. It is not a 100% working solution, but still better than direct tap water.
8. Pest Attack & Diseases
Even if you provide proper care of your anthuriums, small bugs and insects will find a way to your plants.
These tiny sap-sucking insects are really a problem for your plant leaves. Most of the time, they settle underneath the leaves and start sucking the nutrients from the leaves.
These insects multiply very quickly, and within no time you are going to fight an army of mealybugs! These insects will trigger all the commonly seen leaf problems like curling, yellowing, brown spots, drying and wilting.
How to remove pests and insects?
If you find these tiny insects or pests in your anthurium, then you must isolate this plant on priority. Also, check all the plants nearby, because these bugs move to nearby plants very quickly.
Once your infected anthurium is isolated, you need to clean the leaves using pesticides. For tiny pests, homemade pesticides like neem oil is more than enough. If the infection is severe and invasive, use alcohol or other chemical-based pesticides in diluted form.
9. Natural Aging
If you don’t see any of the above problems in your anthurium plant, then probably you’re scratching your head on something that is normal and natural.
When your plant grows a lot of new leaves, some of the matured leaves will start to turn yellow and brown. It is completely normal and there is nothing to worry about.
Since it is a completely normal process, there is nothing you can do to prevent it. If the yellow leaves are making your plant looks bad, then prune those matured leaves and leave your plant on its own.
Some people try to add a little more fertiliser thinking that it will give more energy to the plant to focus on new and old leaves, but it won’t work like that. Instead, it will make way for problems like a mineral salt buildup.
Anthurium Yellow Leaves – Frequently Asked Questions (FAQs)
In this section, I will be answering some of the most commonly asked questions related to anthurium leaves turning yellow and brown so that you don’t have to search separately.
How do you fix yellow leaves on anthurium?
Fixing the yellow leaves on your anthurium starts by finding the root cause. Yellowing of leaves can occur due to a variety of reasons like overwatering, underwatering, too much sunlight, overfeeding, etc. Once you’ve found out the root causes, prune off the yellow leaves and fix that particular problem that causes yellow leaves.
Will yellowing of leaves indicate dying of anthurium?
Yellowing of leaves is not always a symptom of your anthurium dying. But, yellowing of leaves is one of the symptoms of serious plant problems like root rot, bacterial blight, etc. So, don’t just neglect yellow leaves, instead check for other serious symptoms and take action accordingly.
Anthurium yellow and brown leaves are a major problem that is concerning a lot of houseplant owners.
It is understandable that unhealthy yellow leaves are not a good sign and you want to get rid of them immediately, but before touching your plant you need to sit back and find out the root cause.
Once you find out the real reason, prune those leaves and follow the advice given to fix the problem.
To back up the information we provide in our articles, the Plantials team only uses high-quality sources published in peer-reviewed university or scientific research journals.